1. Field of The Invention
This invention relates to an arrangement for processing received data in a TDMA (Time Division Multiple Access) communications system and a method therefor, and more specifically to such an arrangement and method each of which features fast processing of received data and also allows the subsequent unit to handle same with high speed, and still more specifically to such an arrangement and method by which control information or signals (viz., control data) contained in bursts can be processed with high speed and high efficiency in the arrangement itself and in the subsequent unit.
2. Description of the Prior Art
In the TDMA system, each earth station (viz., reference or traffic station) transmits bursts in a manner that each burst is located within an allocated time slot of each consecutive TDMA frame. The burst therefore has the same period as the TDMA frame.
The control information or signal of each earth station is split up using time-division multiplexing and is chronologically transmitted within bursts over one multiframe which consists of a predetermined number of frames. The control signal is used for controlling and monitoring the equipments of the TDMA communications system. It is therefore necessary to extract the control signal of each earth station from the corresponding bursts to reproduce same at a receiving side before processing same.
According to one known method, the divided portions of control signals transmitted from multiple earth stations are extracted from consecutive frames of one multiframe in the receiving order, and are successively stored in an appropriate memory. The divided portions thus stored are read out, in the received order, from the memory during the next multiframe duration, and are combined to reproduce each control signal in order to be processed. Consequently, the prior art has encountered a problem that if the receiving order (the order of reception) changes or if the number of earth stations joining the TDMA system change, then it requires a large amount of time to process the control signals due to complex retrieval as well as change of processing order.
According to another known technique, the segments of control information are grouped according to their respective earth station and then stored. Thereafter, the control signal is processed using vacant time periods such as the guard time between bursts and open time slots not occupied by any earth station. However, this prior art has encountered difficulty in a manner similar to that described in connection with the aforesaid known method.
Further, with the recent advent of communicating via a satellite using a spot beam antenna, the accompanying increase of control information makes the aforesaid prior art problem even more outstanding in that an earth station is usually unable to receive its own transmitting data directly from same spot beam antenna.